Bow with take-up cables anchored to riser

ABSTRACT

A bow includes a riser, a pair of limbs, two pulleys, and a bow string set. Each pulley includes a primary wheel and a secondary wheel adjacent to the primary wheel. The bow string set includes a let-off cable, a first take-up cable and a second take-up cable. The let-off cable has opposite ends respectively trained about the primary wheels of the pulleys. The first take-up cable has one end strung about the secondary wheel of one of the pulleys, and the other end anchored to a right rear side of the riser, without extending across a launching path of the bow. Similarly, the second take-up cable has one end strung about the secondary wheel of the other pulley, and the other end anchored to a left rear side of the riser, without extending across the launching path of the bow.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a bow, such as a crossbow or a compound bow, and more particularly to a bow having a bow string set with two take-up cables each anchored to a rear side of a riser of the bow.

2. Description of the Related Art

One type of compound bow is illustrated in U.S. Pat. No. 3,486,495 (1969). In this bow, rotatable, variable leverage pulley members are equipped on the tips of the bow limbs. A bowstring is wound over the pulley members to provide mechanical advantage, and less force is required to hold the bowstring in a fully drawn position than to hold the bowstring at an intermediate draw position. Similar to the compound bow, a crossbow also employs the pulley members to provide similar functions.

FIG. 5 illustrates a conventional crossbow 900, comprising a stock 91, a riser 92 positioned at a front of the stock 91, two limbs 93, 94 with front ends attached to opposite ends of the riser 92, two eccentric pulleys 95, 96 respectively mounted to rear tips of the limbs 93, 94 and a bow spring set 97. Each of the eccentric pulleys 95 (or 96) is consisted of a primary wheel 951 (or 961) and a relatively smaller secondary wheel (not shown). The bow spring set 97 includes a let-off cable 970 and two substantially Y-shaped take-up cables 971, 972.

Specifically, the let-off cable 970 has opposite end portions respectively trained about the two primary wheels 951, 961 of the eccentric pulleys 95, 96. Each of the take-up cables 971 or 972 has one end trained about one of the secondary wheels, and the other end anchored to the other secondary wheel. In other words, the two take-up cables 971, 972 both extend across a launching path R1 of the crossbow 900, which unfortunately may interrupt the launching of a projectile (not shown) which is placed on a track 910 of a stock 91. In order to solve this problem, a slot 910 is defined in a front of the stock 91 so as to permit the take-up cables 971, 972 to pass therethrough and keep away from the launching path R1. However, this configuration has disadvantages in that the slot 910 would have to be specially formed, thus raising the cost of the bow and lessening the strength of the front of the stock 91. This would further cause a lower collimation degree of the track 910 of the stock 91 by which the launching of the projectile would be adversely affected.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a bow to solve the aforementioned problems. The bow includes a riser, a pair of limbs attached to opposite ends of the riser, two pulleys respectively mounted on rear tips of the limbs, and a bow string set. Each pulley includes a primary wheel and a secondary wheel adjacent to the primary wheel. The bow string set includes a let-off cable, a first take-up cable and a second take-up cable. The let-off cable has opposite ends respectively trained about the primary wheels of the pulleys. The first take-up cable has one end strung about the secondary wheel of one pulley, and the other end anchored to a right rear side of the riser, without extending across a launching path of the bow. Similarly, the second take-up cable has one end strung about the secondary wheel of the other pulley, and the other end anchored to a left rear side of the riser, without extending across the launching path of the bow.

Preferred embodiment of the invention may have the following additional characteristics, either alone or in combination:

A stock is employed to be connected to a rear side of the riser. The stock defines in its top a track for receiving a projectile and has at its bottom a trigger for launching the projectile. The riser may have two hook portions respectively positioned on the right and left rear sides of the riser to engage with the first and second take-up cables.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top side perspective view of a bow in accordance with the preferred embodiment of the present invention;

FIG. 2 is a bottom side perspective view of the bow shown in FIG. 1;

FIG. 3 is a partial enlarged view of the bow shown in FIG. 1;

FIG. 4 is a partial enlarged view of the bow shown in FIG. 2; and

FIG. 5 is a prior art.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In the accompanying drawings, a crossbow 100 is illustrated which includes a stock 1, a riser 2 disposed in a front of the stock 1, a pair of limbs 3, 4 connected at their front ends in fixed relation to the riser 2, two pulleys 5, 6 respectively mounted on rear tips of the limbs 3, 4, a bow string set 7 connecting the two pulleys 5, 6, and a stirrup 8. Each of the pulleys 5 (or 6) includes a primary wheel 51 (or 61) and a secondary wheel 52 (or 62) adjacent to the primary wheel 51 (or 61), as best seen in FIGS. 3 and 4.

Referring back to FIG. 1, the stock 1 has in its top a track 10 for receiving a projectile (not shown) and at its bottom a trigger 12 for discharging the projectile. Once the trigger 12 is squeezed, the projectile would go off along the track 10, viz launching path (R2), as known in the art.

The bow string set 7 includes a let-off cable 70, a first take-up cable 71 and a second take-up cable 72. The let-off cable 70 has one end trained about the primary wheel 51 of the right pulley 5, and the other end trained about the primary wheel 61 of the left pulley 6. The first take-up cable 71 has one end strung about the secondary wheel 52 of the right pulley 5, and the other end extending in a direction toward the riser 2 and anchored to a hook portion 21 on the right rear side of the riser 2. Similarly, the second take-up cable 72 has one end strung about the secondary wheel 62 (FIG. 4) of the left pulley 6, and the other end extending in a direction toward the riser 2 and anchored to a hook portion 22 on the left rear side of the riser 2. That is to say, neither first take-up cable 71 nor the second take-up cable 72 extends across the launching path R2 of the crossbow 100. This ensures that the projectile can be discharged without any interrupt of the first take-up cable 71 or the second take-up cable 72, and therefore no slots will be needed to be defined in the front of the stock 1 as taught in the prior art. Thus, the crossbow 100 can be produced at relatively lower cost with higher rigidity and higher collimation degree of the track 10 of the stock 1 for launching the projectile.

It should be noted that, although the pulleys 5, 6 shown in the preferred embodiment are both eccentric pulleys, any type of pulleys may be used as dictated by the convention. For example, one may be idle while the other be an eccentric pulley. Moreover, although the bow 100 shown in the preferred embodiment is a crossbow, the present invention may also be applied to a compound bow where no stock is employed, as long as the two take-up cables of the compound bow do not extend across the launching path R2 of the bow.

It is to be understood that the disclosed embodiments are illustrative in nature and the invention is not to be limited to any one or more embodiments except as set forth in the following claims. 

1. A bow comprising: a riser having two hook portions respectively positioned on right and left rear sides of the riser; a pair of limbs attached to opposite ends of the riser; two pulleys respectively mounted on rear tips of the limbs, each pulley including a primary wheel and a secondary wheel adjacent to the primary wheel; and a bow string set including a let-off cable, a first take-up cable and a second take-up cable; the let-off cable having opposite ends respectively trained about the primary wheels of the pulleys; the first take-up cable having one end strung about the secondary wheel of one of the pulleys, and the other end anchored to the hook portion on the right rear side of the riser, without extending across a launching path of the bow; and the second take-up cable having one end strung about the secondary wheel of the other pulley, and the other end anchored to the hook portion on the left rear side of the riser, without extending across the launching path of the bow.
 2. A bow as recited in claim 1, further comprising a stock connected to a rear side of the riser, wherein the stock has in its top a track for receiving a projectile and at its bottom a trigger for launching the projectile.
 3. (canceled)
 4. A bow as recited in claim 1, wherein at least one of the pulleys is eccentric. 